To see the NAV work as intended: Pls hover over the NAV or the blue Layer and then start scrolling.  

 

 

When scrolled down I expect the background-color of the NAV-Element to change to YELLOW.

 

 

When scrolled BACK UP to the very TOP, I expect the background-color of the NAV-Element to become RED.
This is the Functionality the Template MOD suggests. The Code of the Mod is completely unchanged.